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摘要: 本文报道了用国产石墨型氮化硼(gBN)为原料在炸药爆炸产生的冲击波作用下合成纤锌矿型氮化硼(wBN)的技术。对冲击波作用后的回收产物进行化学分离,得到杂质含量低于0.5%的wBN产品;回收产物的wBN的转化率高于50%;单发试验产量达11~12 g。目前已利用这一技术生产出少量wBN产品。在相同的冲击波条件下,对四种不同来源的gBN进行了合成试验。发现wBN的转化率强烈地依赖于原始gBN的结晶特性。比表面积测量及X射线衍射观察表明,冲击波合成的wBN是一种多晶微粉,平均颗粒度约0.1 m,平均晶粒度约17.5 nm。差热分析显示放热反应起始温度为1 055 K,峰顶温度1 238 K。Abstract: Reported in the paper are techniques of wurtzite type boron nitride (wBN) synthesis from graphite type BN (gBN) by means of shock compressions created via explosive detonation. Recovered samples after shock processing are treated with molten alkalis and hydrochloric acid. Despite that the domestic gBN materials we used are far inferior, both in the crystallinities and particle sizes, to those used in foreign countries for the purpose of shock synthesis of wBN, the yield of our wBN reaches 11 to 12 g per shot, with a convertion ratio over 50%; X-ray diffraction and x-ray fluorescence spectrometry analyses reveal that the total impurity content of this chemically extracted wurtzite type boron nitride product is less than 0.5%. Four different starting gBN from different manufacturers were used in the experiments to synthesis wBN under the same conditions of shock compressions. It is found that the yield of wBN is closely related to the crystallinity of the starting gBN materials. Specific area measurements and XRD analysis indicate that our wBN is a polycrystal super-fine powder material with average particle size of 0.1 m, which consists of many primary crystallites of 17.5 nm in dimension. Thermal stability of our wBN powder is characterized by the emergence of an exothermic peak in the atmospheric gas condition from DTA analysis. Initial temperature of this exothermic reaction is about 1 055 K and peak temperature 1 238 K.
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Balchan A S, Cowan R. US Pat 3667911, 1972. Bundy F P, Kasper J S. J Chem Phys, 1967, 46(9): 3437-3446. Chinose I, Watatsuki M, Aoki T, et al. Synthesis of Polycrystalline Cubic BN(V). In: The proceedings of the fourth international conference on high pressure. Kyoto, Japan, 1974: 436-440. Soma T, Sawaoka A, Saito S. Synthesis of dense form boron nitride and diamond by shock compression. In: The proceedings of the fourth international conference on high pressure. Kyoto, Japan, 1974: 446-453. Akashi T, Sawaoka A B. Dense boron nitride synthesis. In: Graham R A, Sawaok A B. High pressure explosive proceedings of ceramics. Chap. 6. Trans Tech Publ, 1987: 88-117. Sawaoka A B. Akashi T. Very high pressure sintering of shock synthesized wurtzite type boron nitride powders. In: Graham R A, Sawaok A B. High pressure explosive proceedings of ceramics. Chap. 6. Trans Tech Publ, 1987: 119-138. Bergmann O R. Bailey N F. Explosive shock synthesis of diamond. In: Graham R A, Sawaok A B. High pressure explosive proceedings of ceramics. Chap. 6. Trans Tech Publ, 1987: 65-86. 石川欣造, 泽冈昭, 田中良平, 等. 开拓未来的新材料. 王魁汉, 郝士明, 王君超, 等译. 北京: 治金工业出版社, 1989. Araki M, Kuroyama Y. Physica B, 1986, 139-140: 819-821. Dremin, et al. Method of producting wurtzite-like boron nitride. Canadian Patent 4014979, 1977. Corrigan F R, Bundy F P. J Chem Phys, 1975, 63(9): 3812-3820. Ададуров Г А. Успехи Химии, 1986, 55(4): 555 Дрймин А Н. Горение и Взрыв. In: Материалы Ⅳ-20 Всесоюзного Симпозиума по Горению и Взрыву. Москва: ИЗД Наука, 1977: 88. Верещагин А Л, Сакович Г В, и др. ДАН СССР, 1990, 314(4): 866. 冯士光. 新型超硬材料立方氮化硼聚晶及其刀具的应用. 成都: 四川科学技术出版社, 1984.
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